What I have noticed is that very often the problem with these "fun" jobs isn't that there is limited demand for them on the employer's side, rather the problem is that the profession of a game tester requires game developers. Some of the jobs are more popular than others. If you need two testers for every software developer working on a game and game testing is far more popular than game development, then game testing becomes a sweatshop activity because there aren't enough game developers to absorb all the people willing to become game testers.